1. Field of the Invention
The present invention relates to a tire vulcanization mold for vulcanizing green tires.
2. Background Information
When manufacturing a pneumatic tire, a tire vulcanization mold is used to vulcanize a green tire to which tire configuration members are attached. By heating the tire vulcanization mold, the green tire is vulcanized, and a tread pattern is formed in a surface of the tire tread portion by recesses and protrusions provided in a tire molding surface of the tire vulcanization mold.
However, during the vulcanization process, unnecessary air may become trapped in the tire vulcanization mold. Additionally, gas produced as a result of vulcanization can become trapped in the tire vulcanization mold. This air and/or gas exists between the tire molding surface of the tire vulcanization mold and the green tire, which leads to portions of the green tire not being sufficiently heated. As a result, rubber material of the green tire may not flow well and vulcanization defects caused by rubber filling shortages and the like can occur in the surface of the vulcanized tire. Therefore, tire vulcanization molds are provided with exhaust mechanisms for evacuating air or gas produced when vulcanizing out of the mold.
An example of an exhaust mechanism in the tire vulcanization mold is described in Japanese Unexamined Patent Application Publication No. 2009-269363. In this exhaust mechanism, an elongated hole is provided in the tire molding surface of the tire vulcanization mold, and a blade is embedded in the hole. Thereby, the exhaust mechanism has a structure where a small gap is formed between the blade and a long edge of the hole. Air and/or gas is evacuated out of the tire vulcanization mold via this small gap.
The blade used in the tire vulcanization mold described in Japanese Unexamined Patent Application Publication No. 2009-269363 is fixed in the elongated hole and, therefore, is embedded so as to be abutted against a portion of the long edge of the elongated hole. As a result, the small gap is not formed throughout an entire length of the long edge of the elongated hole, and an area of the small gap that opens to the tire molding surface is reduced. Thus, from the perspective of sufficiently utilizing the elongated hole as an exhaust groove, improvements can be made to this type of tire vulcanization mold.